GREENE: Google is buying the Frommer's travel guide business from a New York publisher. The search giant is trying to offer more robust travel-related results and, of course, sell more ads.

Here's NPR's Wendy Kaufman.

WENDY KAUFMAN, BYLINE: When Seth Kugel, who writes the Frugal Traveler column for The New York Times, first heard about the deal, he thought...

SETH KUGEL: Great. I mean, if Frommer's content ends up on line for free, that will save cheapskates like me a lot of time sitting on the floor of the local Barnes and Noble and scrolling down notes from guidebooks there.

KAUFMAN: Frommer's is a huge name in travel. It's been producing authoritative guidebooks for well over half a century. They're based on rigorous research and are written by pros.

That's quite different from what's found on sites like TripAdvisor or Travelocity. Last year, Google bought Zagat another well-respected travel and leisure publication.

Google isn't saying exactly what its plans are for Frommer's - but some observers are wary of the company's increasing market power in online travel. They fear search results could unfairly favor Frommer's or Zagat's content over material from other sites.

And writer Seth Kugel has another concern.

KUGEL: I definitely know some quality writers that write for Frommer's and I'm certainly worried that they will no longer have the same resources to use to travel and do real travel writing and real criticism.

KAUFMAN: But there's little doubt the addition of Frommer's has the potential to make Google's travel-related search results richer and more interesting.

And Clark Fredricksen, of the research firm eMarketer, says that should make advertisers even more eager to spend their money on Google.

CLARK FREDERICKSEN: Digital advertising spending on sites like Google by the travel and leisure is growing very quickly. It's about a $3 billion market in the U.S., so there are a lot of dollars at stake.